Auxiliary Heating

External heating brings the plasma to fusion temperature and drives current; its power is the denominator of Q_sci, so efficiency is central.

Getting to fusion temperature

Ohmic heating from the plasma current alone cannot reach fusion temperatures, because plasma resistance falls as it gets hotter. Auxiliary heating makes up the difference. The main methods are neutral-beam injection, which fires energetic neutral atoms that ionize and share their energy, and radio-frequency heating, which couples electromagnetic waves to particle motion at resonant frequencies.

The heating power is exactly the denominator of the gain: Q_sci 3.076 is 85.0 MW of fusion power divided by this input. Every megawatt of heating that could be avoided — through better confinement or more self-heating — raises the gain. Heating systems also do double duty, driving non-inductive current and helping shape the current profile.

The efficiency stakes

Heating systems are not perfectly efficient, and their wall-plug losses are one reason scientific gain and engineering gain differ so much. For the foundry, what matters at the plasma is the coupled power in the Q_sci definition; how efficiently the plant delivers it is a separate, larger consideration that the machine deliberately does not fold into its gain claim. The specific heating mix and coupled power for Hyperion are design-and-simulation results.

• Neutral beams and RF supplement ohmic heating
• Heating power is the denominator of Q_sci 3.076
• Heating also drives current and shapes the profile

This page describes a design-and-simulation study, not a built machine. Construction begins Q2 2027; first-of-a-kind first tritium is targeted near 2030. No hardware net-gain is claimed before FOAK.